Developing a Novel Prosthetic Hand with Wireless Wearable Sensor Technology Based on User Perspectives: A Pilot Study.

Myoelectric hands are beneficial tools in the daily activities of people with upper-limb deficiencies. Because traditional myoelectric hands rely on detecting muscle activity in residual limbs, they are not suitable for individuals with short stumps or paralyzed limbs. Therefore, we developed a novel electric prosthetic hand that functions without myoelectricity, utilizing wearable wireless sensor technology for control. As a preliminary evaluation, our prototype hand with wireless button sensors was compared with a conventional myoelectric hand (Ottobock). Ten healthy therapists were enrolled in this study. The hands were fixed to their forearms, myoelectric hand muscle activity sensors were attached to the wrist extensor and flexor muscles, and wireless button sensors for the prostheses were attached to each user's trunk. Clinical evaluations were performed using the Simple Test for Evaluating Hand Function and the Action Research Arm Test. The fatigue degree was evaluated using the modified Borg scale before and after the tests. While no statistically significant differences were observed between the two hands across the tests, the change in the Borg scale was notably smaller for our prosthetic hand (p = 0.045). Compared with the Ottobock hand, the proposed hand prosthesis has potential for widespread applications in people with upper-limb deficiencies.

Association between Sarcopenia and Balance in Patients Undergoing Inpatient Rehabilitation after Hip Fractures: A Retrospective Cohort Study.

Background and Objectives: Sarcopenia is characterized by a decline in skeletal muscle mass, strength, and function and is associated with advancing age. This condition has been suggested as a factor that negatively influences the functional outcomes of patients with hip fractures. However, the association between sarcopenia and balance impairment in patients undergoing inpatient rehabilitation after hip fractures remains unclear. In this retrospective cohort study, we aimed to investigate the impact of sarcopenia on balance outcomes in patients undergoing inpatient rehabilitation following hip fractures. Materials and Methods: Baseline sarcopenia was diagnosed using skeletal muscle mass index and handgrip strength, with cut-off values recommended by the Asian Working Group for Sarcopenia. The primary outcome was balance, which was assessed using the Berg Balance Scale (BBS) at the time of discharge. A multiple linear regression model analyzed the association between sarcopenia and balance. The model was adjusted for age, sex, comorbidities, and cognitive function. Results: Among the 62 patients (mean age: 78.2; sex: 75.8% women), 24.2% had sarcopenia. Patients with sarcopenia had significantly lower BBS scores than did those without sarcopenia (41 vs. 49 points, p = 0.004). Multiple linear regression analysis revealed that baseline sarcopenia was independently associated with BBS scores at discharge (ß = -0.282, p = 0.038). Conclusions: Following inpatient rehabilitation, patients with baseline sarcopenia had inferior balance outcomes than did those without sarcopenia at discharge. Sarcopenia should be assessed on admission to consider and provide additional care for those with a higher risk of poor functional outcomes. More studies are needed to investigate the association between sarcopenia and functional outcomes, examine the impact of sarcopenia treatment on these outcomes, and reduce the risk of recurrent falls and fractures in patients with hip fractures.

Factors Associated with Discharge Destination in Patients with Bone Metastases.

Background and Objectives: The discharge destination of patients with advanced cancer correlates with their quality of life. Patients with bone metastases often undergo lifestyle changes owing to pain and activity limitations. However, there are few reports on factors related to the discharge destination of patients with bone metastases. This study aimed to elucidate the factors associated with the discharge destination of patients with bone metastases. Methods: This study included 278 patients diagnosed with bone metastases who were admitted to the University of Tsukuba Hospital between April 2015 and March 2020. This study examined discharge destination, occurrence of skeletal-related events (SREs), primary lesions, locations of bone metastases, functional ambulation categories (FAC), age, and length of hospital stay. A binomial logistic regression analysis was conducted to compare the home and non-home discharge groups. Results: Of the 278 patients, 142 were discharged to home, 89 were discharged to somewhere other than home (non-home), and 47 died. The discharge destination was associated with spinal cord compression (SCC) (odds ratio [OR] 3.37, 95% confidence interval [CI] 1.35-8.43), hypercalcemia (OR 6.84, 95% CI 1.09-42.76), and FAC at admission (OR 0.45, 95% CI 0.35-0.58). The admission FAC cut-off value for discharge to home was determined to be 1.5 (area under the curve [AUC] 0.79, sensitivity 77.5%, specificity 68.5%). Conclusions: Factors associated with discharge destination were identified. The walking ability required for discharge to home was FAC 1.5, meaning that the patient needed one person to assist in preventing falls when walking on level ground. A cut-off value for FAC on admission for predicting outcomes was identified, suggesting the importance of gait ability assessment on admission.

New balance capability index as a screening tool for mild cognitive impairment.

BACKGROUND: Mild cognitive impairment (MCI) is not just a prodrome to dementia, but a very important intervention point to prevent dementia caused by Alzheimer's disease (AD). It has long been known that people with AD have a higher frequency of falls with some gait instability. Recent evidence suggests that vestibular impairment is disproportionately prevalent among individuals with MCI and dementia due to AD. Therefore, we hypothesized that the measurement of balance capability is helpful to identify individuals with MCI. METHODS: First, we developed a useful method to evaluate balance capability as well as vestibular function using Nintendo Wii balance board as a stabilometer and foam rubber on it. Then, 49 healthy volunteers aged from 56 to 75 with no clinically apparent cognitive impairment were recruited and the association between their balance capability and cognitive function was examined. Cognitive functions were assessed by MoCA, MMSE, CDR, and TMT-A and -B tests. RESULTS: The new balance capability indicator, termed visual dependency index of postural stability (VPS), was highly associated with cognitive impairment assessed by MoCA, and the area under the receiver operating characteristic (ROC) curve was more than 0.8, demonstrating high sensitivity and specificity (app. 80% and 60%, respectively). CONCLUSIONS: Early evidence suggests that VPS measured using Nintendo Wii balance board as a stabilometer helps identify individuals with MCI at an early and preclinical stage with high sensitivity, establishing a useful method to screen MCI.

Postoperative Acute-Phase Gait Training Using Hybrid Assistive Limb Improves Gait Ataxia in a Patient with Intradural Spinal Cord Compression Due to Spinal Tumors.

Sensory ataxia due to posterior cord syndrome is a relevant, disabling condition in nontraumatic spinal cord dysfunction. Ataxic gait is a common symptom of sensory ataxia that restricts activities of daily living. A 70-year-old woman with severe sensory disturbance was diagnosed with intradural extramedullary spinal cord tumors found in the thoracic spine region (T8). Surgical management of the tumors was performed. The patient received gait training 20 days after surgery (postoperative acute phase) using a hybrid assistive limb (HAL). HAL is a wearable exoskeleton cyborg that provides real-time assistance to an individual for walking and limb movements through actuators mounted on the bilateral hip and knee joints. Walking ability was assessed using the 10 m walking test, which included evaluating walking speed, step length, and cadence in every session. To evaluate the immediate effects of HAL training, walking speed and step length were measured before and after the training in each session. During the 10 m walking test, gait kinematics and lower muscle activity were recorded using a motion capture system and wireless surface electromyography before the first session and after completion of all HAL sessions. After the HAL training sessions, improvement in the patient's gait performance was observed in the gait joint angles and muscle activity of the lower limb. After 10 training sessions, we observed the following changes from baseline: walking speed (from 0.16 m/s to 0.3 m/s), step length (from 0.19 m to 0.37 m), and cadence (from 50.9 steps/min to 49.1 steps/min). The average standard deviations of the knee (from right, 7.31; left, 6.75; to right, 2.93; p < 0.01, left, 2.63; p < 0.01) and ankle joints (from right, 6.98; left, 5.40; to right, 2.39; p < 0.01, left, 2.18; p < 0.01) were significantly decreased. Additionally, walking speed and step length improved immediately after completing all the HAL training sessions. This suggests that HAL gait training might be a suitable physical rehabilitation program for patients with sensory ataxia causing dysfunctional movement of the lower limb.

Development of a New Ankle Joint Hybrid Assistive Limb.

Foot and ankle disabilities (foot drop) due to common peroneal nerve palsy and stroke negatively affect patients' ambulation and activities of daily living. We developed a novel robotics ankle hybrid assistive limb (HAL) for patients with foot drop due to common peroneal nerve palsy or stroke. The ankle HAL is a wearable exoskeleton-type robot that is used to train plantar and dorsiflexion and for voluntary assistive training of the ankle joint of patients with palsy using an actuator, which is placed on the lateral side of the ankle joint and detects bioelectrical signals from the tibialis anterior (TA) and gastrocnemius muscles. Voluntary ankle dorsiflexion training using the new ankle HAL was implemented in a patient with foot drop due to peroneal nerve palsy after lumbar surgery. The time required for ankle HAL training (from wearing to the end of training) was approximately 30 min per session. The muscle activities of the TA on the right were lower than those on the left before and after ankle HAL training. The electromyographic wave of muscle activities of the TA on the right was slightly clearer than that before ankle HAL training in the resting position immediately after ankle dorsiflexion. Voluntary ankle dorsiflexion training using the novel robotics ankle HAL was safe and had no adverse effect in a patient with foot drop due to peroneal nerve palsy.

Pain thresholds are unaffected by age in a Japanese population.

INTRODUCTION: Assessment of sensory impairment in diabetic patients by pain threshold test using intraepidermal electrical stimulation (IES) is a recently developed technique. However, there are no normative pain thresholds in healthy people. METHODS: We examined pain, vibration, and pressure thresholds in 178 healthy subjects using IES, vibration perception testing (VPT), and Semmes-Weinstein monofilament testing (SWMT). RESULTS: The mean values for each age group for pain threshold ranged from 0.07 to 0.12 mA. Pain thresholds were unaffected by age. As the age increased, VPT values decreased from 18.0 to 10.6 seconds and SWMT values increased from 21.4 to 45.3 g/mm2 . There were no significant differences in pain threshold, VPT, and SWMT between men and women. DISCUSSION: The pain threshold test appears to be useful for diabetic neuropathy screening because normative values are not affected by age.

Dropped Head Syndrome Attenuation by Hybrid Assistive Limb: A Preliminary Study of Three Cases on Cervical Alignment during Walking.

Background and Objectives: Dropped head syndrome (DHS) is characterized by apparent neck extensor muscle weakness and difficulty in extending the neck to raise the head against gravity. DHS affects forward vision and eating behavior, and hence impairs quality of life. However, standardized treatment of DHS has not yet been established. The purpose of this preliminary study is to seek for a possibility of effective non-surgical, conservative treatment for DHS, by applying a robotic treatment. Materials and Methods: A wearable exoskeleton type robot suit hybrid assistive limb (HAL) was applied to three patients with DHS. A course of HAL treatment included 10 sessions of gait training using HAL. One session lasted about an hour. Case 1 completed the course twice, the first time in two weeks (one session per day) and second time in 10 months (one session per month). Case 2 and Case 3 completed the course once in 10 weeks (one session per week) and in 6 months (one session per 2.5 weeks), respectively. Immediate and lasting effects of HAL on the reduction of cervical sagittal vertical alignment (SVA) during gait was evaluated using a motion capture system. Results: Case 1 showed improvement of cervical alignment during gait after the HAL courses of both different frequencies. Case 2 did not show improvement of cervical alignment during gait. Case 3 showed improvement of cervical kyphosis but not of cervical sagittal alignment during gait. Conclusions: The results of the preliminary study suggest that gait training using HAL may be an effective option of conservative treatment for a part of DHS patients. They also suggest that a lack of immediate effects on the cervical alignment and a lack of ability to perform compensatory trunk motion may indicate a non-responding patient. Generalization of the results requires further research with more cases.

Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study.

PURPOSE: The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. MATERIALS AND METHODS: Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. RESULTS: Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. CONCLUSIONS: These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.

Age-dependent changes in dynamic standing-balance ability evaluated quantitatively using a stabilometer.

[Purpose] The efficacy of a stabilometer-based index of postural stability (IPS) as an indicator of dynamic balance ability was investigated. [Subjects and Methods] Using a stabilometer, we calculated the IPS in 583 healthy subjects (178 males, 405 females) under two conditions (open eyes/hard surface, OE/HS; closed eyes/soft surface, CE/SS). [Results] Results revealed a negative relation between IPS and age. IPS (OE/HS) began to decrease at middle-age (40-60 years old), and then decreased more rapidly during elderly ages (>60 years old). On the other hand, IPS (CE/SS) decreased linearly with increasing age. There was no gender difference between the two IPSs. [Conclusion] These results suggest that IPS can evaluate balance ability quantitatively and without a ceiling effect. It was concluded that IPS (OE/HS) indicates comprehensive balance ability, while IPS (CE/SS) reveals balance ability without compensation by visual acuity and plantar superficial sense.

Spino-pelvic-rhythm with forward trunk bending in normal subjects without low back pain.

A strong correlation between low back pain and tight hamstrings has been reported. However, the effect of tight hamstrings on spinal biomechanics remains unclear. The purpose of the study was to investigate spino-pelvic-rhythm during forward bending of the trunk and to clarify the rhythm features with regard to hamstrings tightness. Eighteen healthy male adults with no history of low back pain volunteered to participate. First, we measured the finger-to-floor distance (FFD) in the upright position and set this parameter to 100 %. Using a spinal mouse, spinal alignment was measured in the following four positions: (1) upright posture­100 % FFD; (2) forward bending­50 % FFD; (3) forward bending­25 % FFD; and (4) forward bending­0 % FFD (fingers in contact with the floor). Changes of the angle of the thoracic and lumbar spine as well as the pelvis were calculated. As an indicator of tight hamstrings, we measured straight leg raising (SLR) angle. From positions 1­2 (phase I), the entire spino-pelvic angle moved in 104°. During this phase, the lumbar spine mainly moved. In the second phase (positions 2­3), it moved in 16°. Interestingly, all but 2 subjects showed a negative angle in the thoracic motion, meaning that the thoracic spine extended 4° during trunk flexion, thus exhibiting paradoxical motion. During this phase, lumbopelvic rhythm showed 2 patterns. In 7 subjects, pelvic motion was greater than lumbar motion, while the remaining subjects showed the opposite. In subjects without tight hamstrings, 83 % showed a pelvis-dominant pattern. Only 7 subjects were capable of position 4. During this phase, only slight motion was noted in the spine, and the majority of the motion occurred in the pelvis. Lumbar and pelvic motion correlated negatively in all phases. SLR angle and pelvic motion correlated strongly during phase III, indicating dominant pelvic movement in flexible subjects. The lumbo-pelvic-rhythm comprises 2 patterns­lumbar dominant and pelvis dominant. In flexible subjects, pelvis movement was dominant. In conclusion, improving tight hamstrings may reduce lumbar loading thereby reducing low back pain.

Spino-pelvic-rhythm with forward trunk bending in normal subjects without low back pain.

A strong correlation between low back pain and tight hamstrings has been reported. However, the effect of tight hamstrings on spinal biomechanics remains unclear. The purpose of the study was to investigate spino-pelvic-rhythm during forward bending of the trunk and to clarify the rhythm features with regard to hamstrings tightness. Eighteen healthy male adults with no history of low back pain volunteered to participate. First, we measured the finger-to-floor distance (FFD) in the upright position and set this parameter to 100 %. Using a spinal mouse, spinal alignment was measured in the following four positions: (1) upright posture-100 % FFD; (2) forward bending-50 % FFD; (3) forward bending-25 % FFD; and (4) forward bending-0 % FFD (fingers in contact with the floor). Changes of the angle of the thoracic and lumbar spine as well as the pelvis were calculated. As an indicator of tight hamstrings, we measured straight leg raising (SLR) angle. From positions 1-2 (phase I), the entire spino-pelvic angle moved in 104°. During this phase, the lumbar spine mainly moved. In the second phase (positions 2-3), it moved in 16°. Interestingly, all but 2 subjects showed a negative angle in the thoracic motion, meaning that the thoracic spine extended 4° during trunk flexion, thus exhibiting paradoxical motion. During this phase, lumbopelvic rhythm showed 2 patterns. In 7 subjects, pelvic motion was greater than lumbar motion, while the remaining subjects showed the opposite. In subjects without tight hamstrings, 83 % showed a pelvis-dominant pattern. Only 7 subjects were capable of position 4. During this phase, only slight motion was noted in the spine, and the majority of the motion occurred in the pelvis. Lumbar and pelvic motion correlated negatively in all phases. SLR angle and pelvic motion correlated strongly during phase III, indicating dominant pelvic movement in flexible subjects. The lumbo-pelvic-rhythm comprises 2 patterns-lumbar dominant and pelvis dominant. In flexible subjects, pelvis movement was dominant. In conclusion, improving tight hamstrings may reduce lumbar loading thereby reducing low back pain.

Effectiveness of a Remote Monitoring-Based Home Training System for Preventing Frailty in Older Adults in Japan: A Preliminary Randomized Controlled Trial.

This study examined whether SUKUBARA®, a remotely managed training system that we developed, could improve skeletal muscle mass and muscle strength in community-dwelling older adults. SUKUBARA® is a composite exercise program that combines lower-load resistance training and balance exercises. Participants were instructed to exercise while watching individually assigned videos on YouTube, such that the research administrators could verify the viewing records of each participant. Fifteen participants (69 ± 4 years) were randomly assigned to the intervention (eight participants; the RT group) or the control group (seven participants; the CO group). The primary endpoint was a change in fat-free mass (FFM; kg), whereas the secondary endpoints included a change in knee extension strength (KES; Nm/kg). Correlation analyses were conducted to examine the relationship between FFM and KES. During the 12-week intervention period, significant differences were observed between the RT and CO groups in the changes in FFM (0.5 ± 0.5 vs. -0.1 ± 0.5) and KES (0.20 ± 0.22 vs. 0.02 ± 0.13), and significant positive correlations were found between the changes. Thus, SUKUBARA®-based interventions have the potential to improve muscle hypertrophy and enhance muscle strength among community-dwelling older adults. Thus, SUKUBARA® -based interventions show promise in improving muscle hypertrophy and enhance muscle strength among community-dwelling older adults. However, appropriately powered future research is needed to replicate these findings.

Verification of the Effects of a YouTube-Based Home-Based (Self-Managed Intervention) Training System Developed for Frailty Prevention: A Pilot Study.

Resistance training is considered the most effective intervention for increasing older people's muscle mass and strength. Thus, we created the Sukubara®, a self-administered training system (squat + balance training) that incorporates a new low-load exercise. In this study, we hypothesize that introducing Sukubara will positively affect skeletal muscle mass and physical function. A preliminary verification was carried out on healthy, non-elderly participants who were recruited from the hospital staff. Participants were randomly assigned to two groups for a 12-week intervention: the resistance training group (R group) that performed the Sukubara exercise program and the control group (C group) that did not. This study's primary end¬point was a change in skeletal muscle mass, while the secondary endpoints were knee extension strength and one-leg standing time with eyes closed. An analysis of the 18 participants (R group = 8; C group = 10) was performed. Results showed that skeletal muscle mass, knee extension strength, and one-leg standing time were significantly improved or tended to be significantly higher in the R group than in the C group. Our study concluded that, by incorporating low-load exercise, Sukubara resulted in muscle hypertrophy and improved physical function.

A Multidisciplinary Rehabilitation Approach for a Patient With Diffuse Large B-cell Lymphoma and Bone Metastasis: A Case Report.

Cancer is often accompanied by bone metastasis, which may lead to skeletal-related events (SREs), such as pain, hypercalcemia, pathological fractures, spinal cord compression, orthopedic surgical intervention, and palliative radiation directed at the bone. Herein, we report the case of a 75-year-old female patient diagnosed with diffuse large B-cell lymphoma (DLBCL) with bone metastasis and a pathological fracture of the right iliac bone. The management strategy and follow-up were determined by a multidisciplinary cancer board comprising physicians, physiatrists, orthopedic surgeons, radiologists, and rehabilitation therapists. A conservative approach was chosen, incorporating a bone-modifying agent and weight-bearing restrictions for the right leg, along with rehabilitation therapy and post-discharge support. A multidisciplinary rehabilitation approach for two months enabled the patient to walk independently upon discharge. She maintains her activities of daily living (ADL) for over six months after discharge without any skeletal issues. This case highlights the effectiveness of a multidisciplinary approach in managing bone metastasis or involvement in patients with lymphoma.

Association between Obesity and Short-Term Patient-Reported Outcomes following Total Knee Arthroplasty: A Retrospective Cohort Study in Japan.

Background: This study investigated the association between obesity and short-term patient-reported outcomes after total knee arthroplasty (TKA). Methods: The primary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index's (WOMAC) pain and function scores. Data were collected preoperatively and 2 and 4 weeks after surgery. Patients were stratified into three groups based on body mass index (BMI): normal weight (BMI < 24.99 kg/m2), overweight (25 ≤ BMI < 29.99 kg/m2), and obese (BMI ≥ 30 kg/m2). The associations between BMI and the WOMAC pain and function scores were assessed using generalized linear mixed models. Results: Among the 102 patients (median age: 75.0, women [85.3%]), 29.4%, 48.0%, and 22.5% were normal weight, overweight, and obese, respectively. The mean pain and function scores at baseline were similar across the BMI-stratified groups (p = 0.727 and 0.277, respectively). The pain score significantly improved 2 weeks post-surgery (p = 0.001). The function score improved significantly 4 weeks post-surgery (p < 0.001). The group and group-by-time interaction effects lacked statistical significance. Conclusions: All patients statistically and clinically showed relevant pain reduction and functional improvement shortly after TKA, irrespective of their obesity status. These data may help healthcare professionals discuss the expectations of pain amelioration and functional improvement with TKA candidates.

Single-Joint Type Hybrid Assistive Limb for Knee Training in the Acute Postoperative Phase After Opening Wedge High Tibial Osteotomy: A Feasibility and Safety Trial.

BACKGROUND AND OBJECTIVE: Opening wedge high tibial osteotomy (OWHTO) influences the knee extensor mechanism, the range of passive motion of knee extension and persistent quadriceps, and anterior knee pain and weakness. Rehabilitation should focus on quadriceps strength and improving joint mobility. The single-joint hybrid assistive limb device (HAL-SJ) is a wearable exoskeleton cyborg. In this study, we investigated the feasibility and safety of HAL-SJ training after the early postoperative period following OWHTO and whether the use of this device can improve functional outcomes, including knee muscle extensor strength and knee extension range of motion without knee pain. METHODS: Patients who had been diagnosed with knee osteoarthritis and had undergone OWHTO were assessed for eligibility in this prospective trial conducted at our institution between June 2015 and November 2020. The participants were split into two groups, i.e., 10 patients in the hybrid assistive limb (HAL) group and eight patients in the control group. We initiated HAL-SJ therapy on postoperative day 8 and continued it until the patient's discharge. During the hospitalization period, patients engaged in HAL-SJ-assisted knee extension exercises. This exercise routine encompassed five sets, each comprising 10 repetitions, and was conducted twice a week. We conducted assessments aimed at detecting any potential adverse events that could be linked to HAL training. Assessment of the knee extension angle via the visual analog scale (VAS) and strength assessments using a hand-held dynamometer (HHD) were conducted. To compare clinical outcomes before and after OWHTO, knee extension angle, the VAS, HHD, Japanese Orthopaedics Association (JOA) score, and the Japanese Knee Osteoarthritis Measure (JKOM) were assessed at four distinct time points. RESULTS: No adverse events were observed during the study. The assessment of clinical outcomes before and after OWHTO demonstrated a gradual improvement in outcomes. CONCLUSION: The single-joint hybrid assistive limb device in patients who underwent OWHTO appears to be potentially safe. It contributed to enhanced muscle activity efficiency by reducing knee pain and improving knee extension angles in the early postoperative phase.

Jack-knife stretching promotes flexibility of tight hamstrings after 4 weeks: a pilot study.

Tight hamstrings are reported to be one of the causes of low back pain. However, there have been few reports on effective stretching procedures for the tight hamstrings. The so-called jack-knife stretch, an active-static type of stretching, can efficiently increase the flexibility of tight hamstrings. To evaluate hamstring tightness before and after the 4-week stretching protocol in healthy volunteer adults and patients aged under 18 years with low back pain. For understanding the hamstrings tightness, we measured two parameters including (1) finger to floor distance (FFD) and (2) pelvis forward inclination angle (PFIA). Eight healthy adult volunteers who had no lumbar or hip problems participated in this study (mean age: 26.8 years). All lacked flexibility and their FFD were positive before the experiment. Subjects performed 2 sets of the jack-knife stretch every day for 4 weeks. One set consisted of 5 repetitions, each held for 5 s. Before and during the 4-week experiment, the FFD and PFIA of toe-touching tests were measured weekly. For 17 of the sports players aged under 18, only FFD was measured. In adult volunteers, FFD was 14.1 ± 6.1 cm before the experiment and decreased to -8.1 ± 3.7 cm by the end of week 4, indicating a gain in flexibility of 22.2 cm. PFIA was 50.6 ± 8.2 before the experiment and 83.8 ± 5.8 degrees after. Before and after the experiment, the differences were significant (p < 0.05). For those aged under 18, FFD was 8.1 ± 8.0 and -9.6 ± 6.8, before and after the stretching, respectively. This difference was significant (p < 0.05). The jack-knife stretch is a useful active-static stretching technique to efficiently increase flexibility of tight hamstrings.

Prevalence of Sarcopenic Obesity and Factors Influencing Body Composition in Persons with Spinal Cord Injury in Japan.

This study aims to investigate the prevalence of sarcopenic obesity and factors influencing body composition in persons with spinal cord injury (SCI) in Japan. Adults with SCI aged ≥ 20 years who underwent whole-body dual-energy X-ray absorptiometry between 2016 and 2022 were retrospectively analyzed. Data from 97 patients were examined. The primary outcome was appendicular skeletal muscle mass (ASM). Multiple linear regression analysis was conducted to assess factors influencing the lean and adipose indices in persons with SCI. Sarcopenia, obesity, and sarcopenic obesity were prevalent in 76%, 85%, and 64% of patients, respectively. Multivariate linear regression analysis revealed that sex (ß = 0.34, p < 0.001), lesion level (ß = 0.25, p = 0.007), severity (ß = 0.20, p = 0.043), and ability to walk (ß = 0.29, p = 0.006) were independently associated with ASM. Sex (ß = −0.63, p < 0.001) was independently associated with percent body fat. In conclusion, sarcopenia, obesity, and sarcopenic obesity were prevalent among patients with SCI in Japan. Female sex, tetraplegia, motor-complete injury, and inability to walk were risk factors for sarcopenia, whereas female sex was a risk factor for obesity in persons with SCI. A routine monitoring of body composition is necessary, especially among those with multiple risk factors, to identify individuals in need of preventive and therapeutic interventions.